NC Graphics Open Offices in South Africa
April 24, 2006
Established in 1977, Cambridge based CADCAM software developer NC Graphics announces the opening of a new independent distribution office in South Africa, NC Graphics (South Africa). This adds to their European offices set up in 1996 based in Germany and their global marketing and distribution with DEPO Frastechnik. With distribution now covering the whole of Europe, Japan, Canada, Korea and China and South Arica.
Since restructuring internally in 2003, NC Graphics has heavily invested in improving both their ToolMaker and DEPOCAM CADCAM software products, and with the additional inspection module - DEPOINSPECT - now available 2006 looks to be an even better year. These products will be on show at the MACH 2006 Hall 5 Stands 5791 and 5784 (15-19 May 2006). But why wait until then? NC Graphics are very keen to demonstrate the enhanced software in the marketplace, and can arrange a personal demonstration for you at any time [+27 (0) 83 658 4748].
Our mission remains to offer technically strong and competitively priced CADCAM systems to the toolmaking and precision engineering industry. NC Graphics (South Africa) will be the distributor of their DEPOCAM software in South Africa.
DEPOCAM, a Practical Strategy for High Speed Machining
While there will always be debate regarding what constitutes high speed machining (HSM), it is generally accepted that the process relates to spindles running in excess of 24,000 rev/min. However, HSM is also a relative term, as spindle speeds must be assessed in practical engineering terms in relation to the size of the cutter (unrealistically high values would be obtained for small diameter tooling) and the material being worked (feed rates and depths of cut would be greater on aluminium than for hardened steel).
Yet there's much more to HSM than just high spindle speeds and fast feed rates. Clearly, high speed axis drives are essential, suitable control software, minimum non-cutting times, effective tooling and the necessary machine rigidity to fully exploit the benefits of the process. However, one key factor often overlooked in the HSM equation, is the actual efficiency of the tool paths generated for the process.
Many CAM systems still adopt traditional machining techniques developed historically and such methodology is not always compatible with today's demands for high speed and high efficiency machining. This is why NC Graphics developed DEPOCAM software from scratch, instead of following an evolutionary path, as is the norm. For this new CAM system, the ethos of the design from the outset was to capitalize on the latest advances in machine tools, controls, tooling and high speed production methods.
The result of all this development effort is a 3D CAM system, which generates optimized tool paths and motion control for all levels of HSM, whether you are using a 10,000 rev/min spindle and 2 m/min feed rates or running at 35,000 rev/min and feeding at 10 m/min. DEPOCAM provides major benefits in terms of shorter programming cycles, faster and more efficient metal removal, reduced lead times, extended tool life, less wear and tear on expensive CNC machine tools and ease of use. As such, the system is proving particularly suitable for roughing complex tool and mould making-type work in die steels using carbide cutting tools on modern CNC mills and machining centers.
Mould manufacture usually centers on the low volume production of intricate, high value items with complex 3D cavities, which require large volumes of metal to be removed from difficult-to-machine materials or hardened tool steels. While intrinsic demands for tight tolerances, the seamless blend of curved surfaces, shallow release angles and high levels of surface finish only serve to compound production and programming problems alike.
Against such a backdrop, however, moulds and dies have to be produced efficiently, economically and in the shortest possible time scales. DEPOCAM has been developed to meet these very demands and that's why the system is now proving so popular with toolmakers all over the world.
The software incorporates a number of special features and routines designed to increase machining speed and promote more efficient and accurate cutting. These include the use of helical-style tool paths, which provide a smoother and overall faster cutter path, where the tool is never overloaded or forced to dwell. This also allows the material to be cleared from the middle of the cutter, so reducing load and wear on the tool and the machine itself. While other characteristics of the software center on: adding radii to roughing tool paths (for continuous linear movement of the cutter), the adoption of climb milling techniques (to promote tool life), boundary control (allowing particular areas to be selected for machining) and the use of rapid motion within the partially-machined work piece (instead of moving in fresh air).
Many CAM systems produce tool paths with sharp corners, which have a detrimental effect on the benefits of HSM. While today's controls can look ahead, anticipate a change in direction and slow the feed down accordingly, this doesn't make for efficient machining. The cutter dwells, which reduces the load on each insert and causes rubbing (which can work harden some steels). While accelerating back into the part again promotes an irregular cutting action, which can significantly reduce tool life. Such non-fluid routines also impinge on machining efficiency as traditional cutter paths programmed to machine at say 2 m/min will average only around 60% of this on a typical part.
DEPOCAM differs in that, the smooth and continuous action of its arc-style tool paths can machine at the programmed feed rate for the whole job. This alone can result in machining timesaving of up to 50% compared with conventional CAM systems.
When moving from one Z level to another, contact is maintained between the cutter and the work piece wherever possible in order to reduce shock loading and improve tool life. Climb milling is usually recommended and the system either helix- or profile-ramps down to the next Z level. When roughing, there is no possibility of making vertical plunge movements, which can quickly chip and even break carbide tooling. Such machining strategies were developed in close collaboration with leading German tooling company along with other cutter and machine tool manufacturers who advised on optimum cutter paths.
DEPOCAM creates tool paths in two main stages, beginning with the passes, which will become the tool path. The second stage is to link the moves that describe how the tool will move from the home position to the work piece, the cutting direction, the connection of individual cutting passes and rapid traverse moves. The system has the ability to rapid within the work piece (instead of retracting to a Z clearance plane outside the job) and this can save much air cutting time on cavity style work. While for finishing, the software has advanced rest-machining features, whereby it is possible to apply any machining strategy including: waterline, raster, radial, spiral, constant 3D offset or parallel pencil milling.
In addition to being easy to use, NC Graphics new software also generates tool paths rapidly. Finally, one other notable aspect of DEPOCAM is that most of the features, which have been designed for high speed machining, can in fact be applied to more conventional milling machines with standard controllers. For even here, the logistics of the CAM system can reduce air-cutting time, lower cycle times and increase surface finish levels for more cost effective and productive machining.
Feed-Rate Optimization
DEPOCAM has feed-rate optimisation for area-clearance, core roughing, rest roughing and water-line machining. The software is aware of the cutting conditions, if the current tool-path is machining on an out-side corner, then the feed-rate specified can be maintained. In areas such as internal corners where the cutter will be in full contact, DEPOCAM looks ahead and adjusts the feed-rate down to maintain accuracy and prolong tool-life. When DEPOCAM is using a helix entry for area clearance roughing, once the cutting tool is to depth, the feed-rate is also reduced, as this first move will be with the full width of the cutter. This is then returned to normal once the cutter is not in full contact.
Vibration Free Machining
When roughing or waterline machining DEPOCAM has an option for anti-vibration look ahead. This feature greatly reduces vibration, an important feature for all machinists. Helps to maintain consistent cutting conditions, prolonging the life of the machine tool and cutting tools, and in turn produces a more accurate part at the roughing and rest roughing stages, enabling the finishing tool-paths to provide consistently more accurate parts with a good surface finish, saving both time and money.
The rest machining in “other CAM products” we have see to-date will only work with ball end cutters and is based on Pencil passes, if a pencil pass can not be made the system will not find the rest areas. The passes also over-lap at the ends. DepoCam 2006 rest machining works with all types of cutter, and is available on all the finish machining routines, Waterline, Raster, Spiral, Radial, Constant Step-over, Parallel Pencil Passes, Corner offset Passes, Morphed and Boundary Passes.
(ENDS)
NC Graphics (South Africa), Cleopatra Close 6, Booysen Park,
Port Elizabeth, South Africa, 6059
Tel: +27 (0) 83 658 4748 Fax: +27 (0) 86 651 2631
Website (South Africa): www.ncgraphics.co.nr Email: ncgsa@justcadcam.co.za
Contact: Mrs Danielle Mohamed, Marketing Manager